Vibration Analyzer VA-12. Vibration Analyzer VA-12

Transcription

1 Vibration Analyzer VA- VIBRATION Vibration Analyzer VA- A N A L Y Z E R

2 Portable vibration analyzer for Equipment Diagnosis and On-site Measurements Vibration Meter VA- With FFT analysis function Piezoelectric Accelerometer PV-57ｴ with integrated preamplifier Magnet attachment supplied Major Application Fields Compact & Lightweight Product Development Vibration measurement at various stages of product development Quality Assurance Pre-shipment testing, post-installation operation checks Vibration Analyzer VA- Maintenance Startup testing after periodic maintenance and servicing Simple Diagnosis Daily routine checks and monitoring of unusual vibration conditions Precision Diagnosis Measurement of problem vibrations and detection of fault sources

3 Vibration Meter Mode Menu Mode Allows simultaneous measurement of acceleration, velocity, displacement, and acceleration crest factor The crisp color TFT display (0 x 30 dots) is easy to read, whether outdoors, indoors, or in a dark location. Vibration meter mode Menu FFT Analyzer Mode Real-time analysis frequency 0 khz Time waveform display and spectrum display with up to 3 00 spectral lines. Envelope processing also supported. Vibration waveform data recording function(0 seconds at analysis frequency 0 khz) Data stored in WAVE file format on memory card (SD card). Timer controlled automatic measurement Spectrum display (3 00 lines) Spectrum after envelope processing USB port allows use of unit as removable disk Bottom view Overlapping of stored data Piezoelectric Accelerometer PV-57 ｴ (supplied) Curled Accelerometer Cable VP-5K ｴ (supplied) (With magnet attachment) (Length 50 to 00 cm) Piezoelectric Accelerometer SD card slot USB port 3 3 List display (top 0) System Diagram USB Mini B - B cable VIBRATION ANALYZER VA- Time waveform display PV-90 ｴ //97 ｴ Accelerometer Cable BNC Adapter VP-5 series VP-5C Accelerometer Cable Charge Converter VP-5 series VP-0 CC-97 USB Printer BL-UI (With integrated preamplifier) Trigger input connector AC adapter connector SD cards used as memory media USB A - Mini B cable VA- Allows recognition of SD card as removable disk, for transfer (copy/move) of stored data Lock Measurement data and setting data can be stored as a set on memory cards. Up to 000 data sets per store name are supported (max. 00 store names). Piezoelectric Accelerometer PV-85/90B etc. AC adapter NC-99 5 MB SD card (supplied) Computer

4 Vibration Meter Mode Displacement / Acceleration / Velocity Simultaneous Measurement of Three Components Vibration explained Mechanical vibrations can be represented as a complex combination of a spring and weight, as shown in the illustration on the right. The basic physical quantities that define vibration are displacement, velocity, and acceleration. By measuring each of these values, the vibration condition can be assessed. Displacement explained Pen Spring Weight Unit: : μm, mm, etc. The movement distance (travel) from a reference point is called displacement. For example, if a car travels a distance of 00 meters, the displacement value is 00 m. When considering vibrations, the movement distance of the vibrating object from the stationary rest position is the displacement, which changes between positive and negative values. 00 m travel Velocity explained Unit : mm/s, m/s, etc. This quantity expresses the amount of change per unit of time. It is related to the vibration energy. For example, if a car travels a distance of 00 meters in 0 seconds, the velocity is the distance (00 m) divided by the time (0 s), i.e. 0 m/s. When considering vibrations, the displacement magnitude and direction change over a short span of time, and the velocity therefore is not usually constant. The following relationship exists: Velocity = displacement x π x vibration frequency 00 m travel = 0 s Acceleration explained = 0 m/s Unit : m/s, mm/s, etc. Acceleration is the change in velocity per unit of time. It is proportional to the impact force or other external force. For example, if a car traveling at a velocity of 0 m/s changes to a velocity of 30 m/s over a period of seconds, the acceleration is the change in velocity (0 m/s) divided by the time ( s), i.e. 0 m/s. When considering vibrations, the velocity and direction change over a short span of time, and the acceleration therefore is not usually constant. The following relationship exists: Acceleration = velocity x π x vibration frequency Values used to express vibration magnitude m 0 s P-P value 0 m/s 30 m/s Acceleration = s 30 m/s ー 0 m/s =0 m/s s Velocity change is 0 m/s Usage of displacement, velocity, and acceleration Displacement Equivalent P-P value P-P value...maximum value of single-sided amplitude...root mean square of instantaneous value P-P value(peak-to-peak value)...maximum difference between highest and lowest value Equivalent peak value...rsm value multiplied by Equivalent P-P value...rsm value multiplied by Crest factor.../ Measurement of vibrations in a low frequency range (below 00 Hz) Cases where displacement as such is critical Assessment of wear and damage related to static deformation, such as the effects of tensile force or compression Assessment of contact risks and machining precision Velocity Measurement of vibrations in a medium frequency range(0 Hz to khz) Detection of imbalance, misalignment, bolt loosening, rattle and play etc. Assessment of vibration severity (ISO 086, JIS B 0906) Assessment of metal fatigue Acceleration Measurement of vibrations in a high frequency range above khz Detection of bearing and gear defects etc.

5 Vibration Meter Mode Applications Simple Diagnosis Vibration magnitude Measuring the magnitude of vibrations is a useful diagnostic technique for ascertaining that machinery is operating normally and checking for signs of possible problems. For example, when vibrations exceeding the reference value in the velocity range (up to 000 Hz) are detected, the presence of an imbalance, misalignment, or loosening condition can be suspected, whereas vibrations in the acceleration range ( khz to about to 5 khz) point to possible bearing or gear problems. Crest factor The crest factor (C.F.) is an indication of the impact characteristics of a waveform. It is determined by the ratio between the RMS and peak values. Higher crest factor values indicate a stronger impact quality. The crest factor of acceleration measurements is useful for detecting the early stages of bearing damage. Crest factor= The vibration waveform of a bearing with a fault in the initial stage is shown in the example below. Compared to the waveform of a normal bearing, the crest factor is higher. Normal bearing ( / = crest factor is small) Bearing with spot damage / = crest factor is large Maintenance Management of Machine Equipment Using an absolute evaluation standard ISO 086- (JIS B 0906 Mechanical Vibration - Evaluation of Machine Vibration by Measurements on Non-Rotating Parts) This is an absolute reference that can be used to judge whether measured vibration data are normal or not. The vibration velocity s are used. Definition of classes Class Small motors from 0 to 5 kw Class Motors from 5 to 75 kw, machinery equipment up to 300 kw mounted on a rigid base Class Large machinery equipment mounted on a rigid base Class Large machinery equipment mounted on a flexible base Periodic vibration measurement serves to detect problems. Representative zone values Class boundary value mm/s Class A Class Class A B A B C A B C D Class B C D C D D A Excellent B Good C Fair D Poor Condition is normal, no action required. Condition is close to normal, no action required, but monitoring required. Close monitoring required, repair action may be required soon. Condition is hazardous, immediate action required. Using a relative evaluation standard trend management Using the normal condition as a reference, threshold values for caution and hazard conditions are set. When the caution level is exceeded, monitoring is reinforced, and detailed diagnosis is performed when the hazard level is exceeded. A commonly used factor for setting the levels is as follows: caution level = to 3 times the normal value, hazard level = to 3 times the caution value. After deciding on the vibration measurement location, measurement direction, and measurement frequency, a time series graph is commonly used for trend management, comprising measurement values and other data. Hazard level Caution level Month 008 Trend management diagram 5

6 FFT Analyzer Mode Motor The Need for Frequency Analysis Fan Vibration amplitude Machinery usually comprises a variety of vibration sources such as motors, gears, bearings, fans, etc. When devising measures to minimize vibrations and when trying to locate the causes of problematic vibrations, measuring only the magnitude of vibrations often will not provide enough information. It is also necessary to perform frequency analysis, in order to determine which types of vibrations exist and what their levels are. As shown in the illustration, the locations where vibrations occur will affect the vibration frequency. Frequency analysis makes it possible to pinpoint vibration sources with greater accuracy. Gear box Spectrum Vibration amplitudes are shown for each frequency. The time waveform is divided into constant intervals, and FFT analysis* is performed for these intervals. A sine wave will have only one line spectrum, but complex machine vibrations will show peaks at various frequencies. Vibration frequency Time Waveform This shows the variations over time at the location of the accelerometer. It provides information that is not available from the spectrum display, such as whether the vibration is normal or impact related, whether it has shifted upwards or downwards, etc. FFT (Fast Fourier Transform) analysis is a type of frequency analysis that is particularly suited to analyzing machine vibrations. FFT Analyzer Mode Applications Product Quality Control When testing products on manufacturing lines for unusual vibrations, frequency analysis can be very helpful. For example, when targeting a specific frequency, it can be determined whether there are vibration components in the adjacent frequency range. Using the frequency spectrum with a known good product as reference, comparative analysis can be applied to pass / fail evaluation. VIBRAT ION ANALYZ ER VA- Comparison to reference spectrum Overlapping of stored data 6

7 FFT Analyzer Mode Applications Precision Diagnosis of Rotating Machinery Precision diagnosis is used to determine the cause of problems as well as the extent, location etc. Bearings Bearing problems will cause a significant increase in acceleration values. As seen in the example, envelope analysis shows the peaks at equal intervals. When the size, number of rolling elements, axis rotation speed and other parameters are known, the primary frequency of the lined-up peaks will provide information about the problem location. When diagnosing a bearing fault, it is necessary to know the repeat cycle of the impact waveform. This can be achieved by envelope processing, using the principle illustrated below. ① Impact waveform due to bearing fault ② Waveform absolute value Repeat cycle Repeat cycle ③ Low-pass filter based envelope processing Repeat cycle Repeat cycle ④ FFT analysis Misalignment Misalignment explained When there is a misalignment, large vibration components that are an integral multiple of the rotation speed will appear in the axis direction. The type of bearing joint affects the multiplication factor. In the example shown here, there are large vibration components with a factor of 3. Imbalance When there is an imbalance, large vibration components at a frequency equal to the rotation speed will appear in the circumferential direction. Vibrations of other frequencies will be largely absent. The vibration amplitude is proportional to the imbalance magnitude. At higher rotation speeds, the vibration amplitude is proportional to the square of the rotation frequency. When two coupled rotating axes are not properly centered on relation to each other, their centers of rotation will not be in linear alignment. This is called misalignment, which can be either relative to the core or the face or a combination of the two. When misalignment occurs, the thrust load on the bearing increases due to end face runout, resulting in shorter bearing life. Core misalignment Face misalignment Core and face misalignment Imbalance explained This is a condition where the center of gravity of a rotating body has shifted from the center line. There are various types of imbalance, including static imbalance, couple imbalance, and dynamic imbalance. When an imbalance occurs, the load on the bearing in the circumferential direction increases, resulting in shorter bearing life. Static imbalance Couple imbalance Dynamic imbalance Measuring the Resonance Frequency of a Structure When an external force at a frequency close to the resonance frequency is applied to a structure, strong vibration will occur. This can lead to breakdown of machinery, product quality degradation, and other problems. In order to guard against such risks, measuring the resonance frequency is very important. In the example shown at right, multiple resonance frequencies at 8 Hz, 98 Hz etc. exist. VIBRATION ANALYZER VA- To measure the resolution frequency, the structure is struck with a hammer or similar and the resulting vibrations are subject to frequency analysis. 7

8 Specifications Standard compliance CE marking (EMC Directive 00/08/EC) Pretrigger Processing starts from data /8 frame time ahead Chinese RoHS (export model for China only) Display Color TFT LCD, 0 x 30 dots, with backlight Warning indication LED (lights up in red to indicate overload) WEEE Directive Japanese display, English display, Time display Input section Number of measurement Memory channels Connector type etc. BNC, CCLD 8 V ma, (CCLD V ma available as factory option) Sensor Piezoelectric Accelerometer PV-57ｴ (supplied) SD cards (max. GB) Sets of measurement values and parameters can be stored on memory card Parameter setting Up to 5 parameter sets can be stored in unit 000 data saved as one store name. Max. number of store names: 00 Input range At sensitivity 0.00 to mv/(m/s) ACC (Acceleration) 0, 3.6, 00, 36, 000, 3 60, m/s (rms) Memory media Store files memory Parameter settings can be stored on memory card Wave files Up to 0 seconds per file (frequency range 0 khz) 3.6, 00, 36, 000, 3 60, 0 000, mm/s (rms) Vibration waveform recorded during FFT processing DISP (Displacement) 0.89,.83, 8.9, 8.3, 89., 83, 89 mm (EQp-p) available when using a computer. At sensitivity.00 to 9.99 mv/(m/s), using PV-57ｴ BMP files Screen capture can be saved as BMP files. ACC (Acceleration), 3.6, 0, 3.6, 00, 36, 000 m/s (rms) Recall function Measurement data can be read from memory card and redisplayed on screen. Resume function Settings are memorized when power is turned off and can be restored at next power-on 3.6, 0, 3.6, 00, 36, 000, 3 60 mm/s (rms) DISP (Displacement) 0.089, 0.83, 0.89,.83, 8.9, 8.3, 89. mm (EQp-p) At sensitivity 0.0 to 99.9 mv/(m/s) Trigger input connector ACC (Acceleration) 0., 0.36,, 3.6, 0, 3.6, 00 m/s (rms) Input/output section USB port 0.36,, 3.6, 0, 3.6, 00, 36 mm/s (rms) disk function device (removable storage device class) DISP (Displacement) , 0.083, 0.089, 0.83, 0.89,.83, 8.9 mm (EQp-p) Measurement range (using PV-57ｴ, High-pass filter 3 Hz, Low-pass filter 0 khz) ACC (Acceleration) 0.0 to. m/s (rms) Continuous measurement, Hz to 5 khz Instantaneous TTL level, ultra mini jack,.5 mm dia. (for CC-) Removable Allows use of memory card inserted in unit as removable storage Printer Dedicated USB printer (BL-Uｴ) can be used for printing, screen hard copy, function and continuous printing of specified memory address range Power 700 m/s DC V ( to 5 V) AC adapter NC-99, eight IEC R6 (size AA) batteries 0. to. mm/s (rms) at 59.5 Hz Battery life DISP (Displacement) 0.0 to 0.0 mm (EQp-p) at 5.95 Hz maximum acceleration (3, normal operation, backlight off) Approx. hours Current consumption Measurement frequency range (electrical characteristics) Ambient temperature and 5 ma (normal operation, backlight off) -0 to +50, 90 % RH or less (no condensation) ACC (Acceleration) Hz to 0 khz humidity conditions for use 3 Hz to 3 khz Dimensions, Weight (H) x 05 (W) x 36 (D) mm; Mass Approx. 850 g (incl. DISP (Displacement) 3 Hz to 500 Hz Supplied accessories Piezoelectric Accelerometer PV-57ｴ, Curled cable, Magnet attachment batteries, with protective cover, PV-57ｴ connected) Acceleration envelope curve khz to 0 khz Filters IEC R6 (size AA) battery x 8, SD card, Protective cover, Shoulder belt Prefilters High-pass filter Hz (acceleration only), 3 Hz, 0 Hz, khz (-0 % point), cutoff slope -8 db/oct Low-pass filter khz, 5 khz, 0 khz (-0 % point), cutoff slope -8 db/oct Option Name Acceleration envelope curve filter High-pass filter khz (-0 % point), cutoff slope -8 db/oct Waveform Analysis Software High-pass filter 3 Hz, Low-pass filter 0 khz, lowest range setting CAT-WAVE Piezoelectric accelerometer Various ACC (Acceleration) 0.0 m/s (rms) or less BNC Adapter VP-5C Charge converter VP-0 SD-CARD 5 MB SD-5M SD-CARD GB SD-G Inherent noise 0. mm/s (rms) or less DISP (Displacement) 0.0 mm (EQp-p) or less A/D conversion bit Dynamic range Maximum 0 db (Acceleration) principle, 5. khz Vibration meter mode CC- AC Adapter NC-99 USB Printer BL-Uｴ ACC (Acceleration) m/s mm/s rms value Thermal Printer Paper (0 rolls) P--30 DISP (Displacement) mm USB Mini B-B Cable (for Printer connection) CC-97 FFT mode rms value, waveform peak value, crest factor BNC-mini plug Cable EQp-p Time waveform, spectrum, Acceleration envelope curve Analysis points 5, 0, 08, 096, 8 9 (3 00 lines) Time window functions Rectangular, Hanning, flat-top Processing Linear average, maximum, exponential averaging, instantaneous value Frequency span 00 Hz, 00 Hz, 500 Hz, khz, khz, 5 khz, 0 khz, 0 khz Display Use only RION supplied cards for assured operation Option Spectrum Zoom Top 0 list, graph display (excluding DC) Waveform Analysis Software X axis : x, x, x, x8, x6 Y axis : N, N = 0 to 0 (x to x0) CAT-WAVE Overlay display with stored data in spectrum mode Time wave form Zoom Graph display CAT- WAVE allows post-processing using stored waveform file data from VA- X axis : x, x, x, x8, x6, x3 Y axis : N, N = 0 to (x to x6 38) Trigger Trigger source External signal Input level Triggered at falling edge of signal at external trigger input Triggered when time waveform crosses a preset level Trigger level can be set in steps of /8 of full scale on one-sided amplitude Slope +/- trigger operation Trigger operation Free-run Processing always carried out, regardless of trigger condition Repeat Processing carried out whenever triggering occurs Single Processing carried out once only when triggering occurs Data are stored according to the setting of Trigger Start Time, Time Store Interval, Store number. Specifications Model Waveform display functions: Scaled time axis, Differential and integral calculus available Display functions of FFT analysis: Power spectrum, Cross spectrum, Transfer function, Coherence, Power spectrum map, Octave map, Differential and calculus for spectrum area Octave band analysis: Analysis frequency ranges:/ octave 0.5 Hz to 8 khz (5 bands), /3 octave 0. Hz to 0 khz (5 bands), / octave 0.36 Hz to khz (80 bands) Time weighting (time constants): ms, 0 ms, 35 ms, F (Fast), 630 ms, S (Slow), 0 s Frequency weighting: Flat, A, C ISO 00 RION CO., LTD. ISO RION CO., LTD. subject to change without notice. Distributed by: Tel: (0) , Higashimotomachi, Kokubunji, Tokyo , Japan Tel: Fax: This product is environment-friendly. It does not include toxic chemicals on our policy. This leaflet is printed with environmentally friendly soy ink on recycled paper Powered by TCPDF ( 090.P.C